* World shares hit six-week low on Fed concerns
* Home Depot, Best Buy shares rise after results
* Futures up: Dow 3 pts, S&P 4 pts, Nasdaq 5.25 pts
By Rodrigo Campos
NEW YORK, Aug 20 (Reuters) - U.S. stock index futures edged higher on Tuesday following the longest losing streak for equities so far this year, with trader focus on retail shares as top names report earnings.
A gauge of global equity markets hit its lowest level in six weeks, tracking the S&P 500 index's Monday close, as unease about an expected cut in U.S. stimulus and related gains in bond yields left investors on edge.
Equity trading continues to be linked to U.S. Treasuries, with higher yields pressuring stocks. The yield on the benchmark 10-year note came in slightly up at 2.83 percent after hitting 2.9 percent on Monday.
"This has been a technical pullback, and with the 10-year yield near 3 percent we are pretty close to reversing it," said Peter Cardillo, chief market economist at Rockwell Global Capital in New York, pointing to what he called a buying opportunity on U.S. equities.
Home Depot, Best Buy and J.C. Penney lead a string of retailers posting results, and their shares all rose in premarket trading.
Cardillo said better results in some of the retailers could be behind the slight uptick in futures, but the market continues to be weak short-term after closing below 1,650 on Monday.
"The technical outlook worsened and we could still test 1,635/1,645" on the S&P 500, he said.
The S&P closed below its 50-day moving average for a second straight day and at its lowest since July 8.
S&P 500 futures rose 4 points and were above fair value. Dow Jones industrial average futures rose 3 points, and Nasdaq 100 futures added 5.25 points.
Home Depot shares gained 3.6 percent in premarket trading after the world's largest home improvement chain raised its yearly outlook after posting a profit beat.
Shares of Best Buy rallied more than 16 percent in premarket trading after the world's largest consumer electronics chain reported a higher quarterly profit.
Urban Outfitters shares gained 8.9 percent premarket, a day after the apparel retailer's quarterly profit beat market estimates.
J.C. Penney shares gained 3.4 percent premarket after it reported same store sales fell 11.9 percent in the second quarter, during which it reverted to a promotions-heavy strategy to try to halt a sharp sales decline.
China-based Trina Solar reported a smaller quarterly loss as it shipped more solar panels to newer markets such as Japan, China and India, and its shares rose 4 percent premarket.